We propose to develop a new method for linking fMRI measurements to neuronal receptive fields. This method has broad applications to many aspects of visual neuroimaging, including plasticity and cortical development. We propose to develop the method first by analyzing the cortical signals that are essential for normal color vision and color constancy. The first Aim continues the development of a new method to create quantitative models of population receptive field properties in primary visual cortex. In the second and third Aims test a set of hypotheses about how scene interpretation interacts with color appearance, and specifically how scene interpretation influences the neural color representation in visual cortex. The second Aim analyzes how perceived depth influences the color signals. The third Aim analyzes how varying illumination, including changes in color and shadows, influence the neural signals. The methods introduced and applied in this grant are part of a broad effort to measure the neural signals in human visual cortex. These signals are essential for reading, object recognition, face perception, depth, and color perception vision and the many functions that are essential to visual health. Quantifying these signals, understanding how they reorganize in different viewing conditions or in response to disease, is essential to diagnosing and ultimately treating a wide variety of visual disorders of cortical origin. PUBLIC HEALTH RELEVANCE Lay language: Recognizing colors, faces, objects or written text depends on the responses of neurons in a healthy brain. This grant introduces a new method for measuring the signals from these neurons. These measurements help understand disease conditions in which people fail to recognize faces (prosopagnosia), see colors (achromatopsia), or no longer recognize written words (alexia).